This parameter is used with the backup disk command unless the --use_vss parameter value is acronis or none.
If the parameter is specified, logs of Microsoft Exchange Server and of other VSS-aware applications (except for Microsoft SQL Server) will be truncated after each successful full, incremental or differential backup.
Do not specify this parameter in the following cases:
If you use Acronis Backup & Recovery 11.5 Agent for Microsoft Exchange Server or third-party software for backing up the Exchange Server data. This is because the log truncation will interfere with the consecutive transaction log backups.
If you use third-party software for backing up the SQL Server data. The reason is that the third-party software will take the resulting disk-level backup for its "own" full backup. As a result, the next differential backup of the SQL Server data will fail. The backups will continue failing until the third-party software creates the next "own" full backup.
If other VSS-aware applications are running on the machine and you need to keep their logs for any reason.
Using this parameter does not result in the truncation of Microsoft SQL Server logs. To truncate the SQL Server log after a single-pass backup, specify the --mssql_truncate_logs parameter.